Egli model

The Egli model is a terrain model for radio frequency propagation. This model, which was first introduced by John Egli in his 1957 paper,^[1] was derived from real-world data on UHF and VHF television transmissions in several large cities. It predicts the total path loss for a point-to-point link. Typically used for outdoor line-of-sight transmission, this model provides the path loss as a single quantity.

Applicable to/under conditions

The Egli model is typically suitable for cellular communication scenarios where one antenna is fixed and another is mobile. The model is applicable to scenarios where the transmission has to go over an irregular terrain. However, the model does not take into account travel through some vegetative obstruction, such as trees or shrubbery.

Coverage

Frequency: The model is typically applied to VHF and UHF spectrum transmissions.

Mathematical formulation

The Egli model is formally expressed as:

$P_{R}=G_{B}G_{M}\left[{\frac {h_{B}h_{M}}{d^{2}}}\right]^{2}\left[{\frac {40}{f}}\right]^{2}P_{T}$

Where,

$P_{R}$ = Receive power [W]

$P_{T}$ = Transmit power [W]

$G_{B}$ = Absolute gain of the base station antenna.

$G_{M}$ = Absolute gain of the mobile station antenna.

$h_{B}$ = Height of the base station antenna. [m]

$h_{M}$ = Height of the mobile station antenna. [m]

$d$ = Distance from base station antenna. [m]

$f$ = Frequency of transmission. [MHz]

Limitations

This model predicts the path loss as a whole and does not subdivide the loss into free space loss and other losses.

References

^ Egli, John J. (Oct 1957). "Radio Propagation above 40 MC over Irregular Terrain". Proceedings of the IRE. 45 (10). IEEE: 1383–1391. doi:10.1109/JRPROC.1957.278224. ISSN 0096-8390. S2CID 51631410.

v t e Radio frequency propagation models
Free space	Free-space path loss Friis transmission equation Dipole field strength in free space
Terrain	ITU terrain model Egli model Longley–Rice Irregular Terrain Model (ITM) Two-ray ground-reflection model
Foliage	Weissberger's model Early ITU model One woodland terminal model Single vegetative obstruction model
Urban	Okumura model Hata model COST Hata model Young model Six-rays model Ten-rays model
Indoor	ITU model for indoor attenuation Log-distance path loss model
Other	VOACAP (HF) Area-to-area Lee model (900 MHz) Point-to-point Lee model (900 MHz) Longley–Rice model (20 MHz - 20 GHz)